Electronic cigarettes are increasingly used by smokers as a substitute for real tobacco cigarettes. In general, electronic cigarettes use a wire coil heater to vaporize liquid nicotine, or other liquid substances. The user's inhalation on a mouthpiece may be detected by a sensor, causing an electronic circuit to supply electrical current from a battery to the heater. The liquid contacts the wire coil heater, which creates the vapor or mist. The user's inhalation typically also draws ambient air into one or more inlets in the electronic cigarette housing. The vapor is entrained in the air flow moving through the housing and is inhaled by the user.
Electronic cigarettes have many advantages over real tobacco cigarettes. Initially, the risks of lung cancer associated with real tobacco cigarettes is largely avoided, as the tar and other chemicals in tobacco linked to lung cancer are simply not present in an electronic cigarette. Electronic cigarettes generate vapor or mist, and not smoke. Consequently, there is no comparable second-hand smoke problem with use of electronic cigarettes. In addition, since there is no burning material in electronic cigarettes, the risk of fire is eliminated.
Many electronic cigarette designs have been proposed and used, with varying degrees of success. Existing designs though have various disadvantages, including short life, poor atomization, nonuniform vapor caused by different sizes of liquid drops, and overheated vapor. Accordingly, there is a need for an improved electronic cigarette.